Check pages (pdf pg.) 77 & 78 of the WDFW hunting publication.
http://wdfw.wa.gov/publications/01184/wdfw01184.pdf

Your area may fall under this partial listing, but there may be other local and RCWs that allow/deny he was doing in your neighbor's backyard.

RCW Target shooting rules do not apply to hunting according to: RCW332-52-145 It specifically states that hunting is regulated by the wdfw in para. 2. and this is from page 72 (pdf pg 77):

Restricted and Prohibited
Hunting Areas
These areas are closed by Fish and Wildlife
Commission action. Other areas may be closed to
hunting by local, state, or federal regulations.

I love how you we have so many rules that a law degree may be required for hunting by 2020.